Malicious PDF — malware analysis report

Static analysis result for SHA-256 61531b05a0b94b7a…

MALICIOUS

PDF

76.3 KB Created: 2021-09-13 19:24:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 82ed59cdf2c327253fc99f24ccb8add7 SHA-1: 97d42cf5521e423bb986c2948be73de14025bd73 SHA-256: 61531b05a0b94b7a0eb263704a4b1c26d2cfc0c11a961028f28852066a62d49b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is part of a link farm, and numerous unknown URLs were extracted, pointing to a potential distribution or phishing campaign. While no scripts were explicitly extracted, the nature of the link farm and the presence of external URIs suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://juentai.com/userfiles/files/70495472181.pdf In PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090603290060.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/5884747764.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/24773505950.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/38009998257.pdfIn PDF document text
    • https://democv.associasuite.com/imagenes/contenidos/files/pogoxoxoxaxolanumululuj.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/maxinuvabebowikelogawuf.pdfIn PDF document text
    • http://collectifff.be/imgdb/accueil/files/nevodemoda.pdfIn PDF document text
    • http://unseretochter.ch/images/file/70490144801.pdfIn PDF document text
    • http://china-guolin.com/filespath/files/20210910183722.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcc1c5f810---99812243009.pdfIn PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/dunapidoxiwa.pdfIn PDF document text
    • http://abwingstop.com/uploads/files/84566400458.pdfIn PDF document text
    • https://hsdinstruments.nl/uploads/files/vopotupijivun.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613492b8a7009---lifar.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/9150328897.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/29528345102.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/fakafog.pdfIn PDF document text
    • https://beldapromosyon.com/calisma2/files/uploads/8184416482.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/25330592549.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/35248724598.pdfIn PDF document text
    • https://feng-shuiworld.com/userfiles/file/62008119716.pdfIn PDF document text
    • https://kapokcmassage.com/uploads/files/202109040630292292.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=dragon+ball+z+mugen+apk+downloadPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c7dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7DC 10856 bytes
SHA-256: 1ec2a45085d5c8089ddcf5032f3db6ba211aa5cd4037d6d855c35e54bac08e83
font_01_sfnt_off0000e086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE086 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f898.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF898 16708 bytes
SHA-256: 30c2b63e895c6b0fa174a1dd9454fe82f73a93373067c4fedb30bf358662b7c2